Because you can't compete at this level by chucking increasing amounts of anything at the problem - people, dollars, spindles, nodes, you name it.
If your problem is extremely transactional and legitimately unshardable, feel free to drop 6 mil on exadata. Or a half a mil on a database server and backup. But frankly, your objections are starting to have a religious feel to them. All I was saying is that PL/SQL is a pile of crap to code in and fundamentally unscalable without spending a boatload of money. A little better design can get the same thing with a lot less cash.
EDIT: No, those are facts, PL/SQL looks like it was designed in 1965 and, yes, putting all of your CPU processing into a single node is fundamentally unscalable. I've seen it. It was fundamentally unscalable.
I'm not making a religious point about RDBMS - it can be the best model in many situations. I'm making a point about single bottlenecks for your architecture.
Oracle tried to market their Exalogic as "no bottlenecks" which is nearly as funny as "unbreakable linux" and "zero latency".